Inclination indicating device



July 7, 1936.

T. L. LYNCH ET AL INCLINATION INDICATING DEVICE Filed May '18, 1932 2Sheets-Sheet l F'IE- Z- INVENTORS THEODOEE L. LYNCH HAQQY L. QILLINGYAr'T ORNEY July 7, 1936.

2 Sheets-Sheet 2 Filed May 18, 1952 FIE. E1-

95 II/ IVIAI'II/l/l/II INVENTOPS THEODORE L. LYNCH BY HAPPY L. PILL/Ne 773 ATTORNEY i wma Patented July 7, 1936 2,046,956 INCLINATION INDICATINGDEVICE Theodore L. Lynch, Sonthgate, and Harry L. Billing, Bellflower,Calif.; said Billing assignor to J. Warren MacClatchie, Compton,

CaliL,

doing business as MacClatchic Manufacturing Company Application May 181932, Serial No. 612,002

25 Claims.

This invention has to do in a general way with devices for indicatinginclination, and is more particularly related to improvements ininclination indicating devices for oil wells of the type shown in ourPatent No. 1,854,208, issued on April 19, 1932.

The device contemplated by this invention like that disclosed in ourpatent above identified has as its primary object the production ofmeans embodied in the drill pipe for obtaining a sensible indication ofinclination through the medium of the drilling fluid.

It is a fundamental object of the present invention to produce a deviceof the class described which embodies a valve situated in the path ofthe circulating fluid, such valve being associated with gravity actuatedmeans and arranged so as to be operated at the option of the driller. Inthe operation of the device contemplated by our.

present invention, the' gravity actuated means does not operate thevalve as in the device shown in our former patent, but is arranged sothat the valve is either closed or opened by the pressure of thedrilling fluid, depending upon the verticality of the pipe. If the valveis closed, the resultant restriction causes an increase in pressurewhich can be observed on asuitable gauge provided in the fluidcirculating system or which,

in the event the valve is constructed so as to completely close thepassage through the pipe, the increase in pressure will be suilicient tostop the operation of the pump.

It is a further object of our invention to produce a device of the classdescribed which may be set or adjusted so that a sensible indication isobtained when the instrument is inclined beyond a predetermined angle.For example, the device may be set so as to give an indication when thedrill pipe is inclined beyond say 2 with the vertical, aninclinationless than this giving no indication.

It is a further object of this invention to produce a device of theclass described wherein the operation is controlled solely through themedium of the fluid circulating pump, and which does not necessitatedisturbing the drill pipe.

The general construction of the device contemplated by this inventioncomprises a suitable barrel or pipe section adapted to be interposed inthe drill pipe, such barrel containing a valve seat. A valve stem issuitably mounted in the barrel for reciprocation therein and this stemcarries a valve adapted to engage the valve seat. The lower end of thevalve stem is provided with a 55 pendulum mounted for universal movementand adapted to engage a suitable pendulum re'st which is mounted in thebarrel .therebelow. The pendulum rest is so constructed and sopositioned as to be engaged by the tip of the pendulum withinpredetermined limits in the inclination of the 5 pipe and is therebyeffective to hold the valve against movement relative to the valve seatin the event the pendulum engages the seat or to permit the movement ofthe valve relative to the seat in the event the pendulum clears thependulum rest. 10

The device may be constructed so that the valve is closed by the actionof a pressure fluid in the event the pipe is inclined and is held openby the pendulum in the event the pipe is vertical; or it maybeconstructed so that the valve is held in 15 a closed position by thependulum in the event the pipe is inclined and is opened by the actionof the pressure fluid in the event the pipe is vertical.

It is a further object of this invention to produce a device of theclass described in which the valve is hydrostatically balanced in thepressure fluid contained in the pipe, such valve being associated withyieldable means to open the same or to move the valve away from the seatwhen the pump is stopped.

It is a further feature of a modified form of I our invention that thedevice is provided with a so-called float valve which may be used tofloat the drill pipe into the well and which also acts as a blow-outpreventer.

It is a further feature of this invention that the device is of simpleform and construction; is not liable to excessive wear; and may beeconomically manufactured.

The details in the construction of a preferred embodiment of ourinvention. together with other objects attending its production, will bebest understood from the following description of the accompanyingdrawings which are chosen for illustrative purposes only, and in which-Fig. 1 is a broken elevation with parts in section showing an oil welldrilling apparatus and illustrating the manner in which our invention isused in connection therewith;

Fig. 2 is a sectional elevation illustrating the details in theconstruction ofa preferred form of our invention;

Fig. 3 is a plan section taken in a plane represented by the line 3-3 ofFig. 2; r

Fig. 4 is a sectional elevation of a modified form of our invention;

Fig. 5 is a plan section taken in a plane represented by the line 5-5 inFig. 4; and

, Fig. 6 is a sectional elevation of another modifled form of ourinvention.

More particularly describing the invention as herein illustrated,reference numeral H indicates a drill pipe which is shown as extendinginto a bore hole l2, and has a drill bit l3 provided on its lower end.The drill bit [3 is shown as being mounted in the lower end portion of abarrel l4 which forms a part of the drill pipe and which .contains theinclination indicating device contemplated by this invention.

The upper end portion of the drill pipe H is provided with a Kelly l5 ofthe usual construction which extends through a rotary table I6, and hasmounted on its upper end a head 11 through which a drilling fluid, suchas rotarymud, is adapted to be pumped into the drill pipe under pressurefrom a conduit system indicated by reference numerals I8 and I9. Thedrilling fluid is forced into the conduit system under pressure by anysuitable means such as the pump 20. Reference numeral 2| indicates apressure gauge which may be provided in the conduit system at anysuitable point for the purpose of indicating an increase in pressure insuch fluid during the operation of the inclination indicating device.

The details in the construction of a preferred form of our invention arebest illustrated in Figs. 2 and 3 where the barrel I4 is shown as beingthreaded at its two ends as indicated by reference numerals 25 and 25for interposition in a drill pipe or the like. Reference numeral 21indicates a shoulder which is formed in the passage through the barreland is adapted to carry a supporting ring 28. Reference numeral 28'indicates a valveseat ring which rests upon the upper edge of thesupporting ring 28 and is shown as being provided with an annular valveseat 29. In order to reduce the liability of wear upon the valve: seat,due to the abrasive action of the circulating fluid, we propose to makethe seat ring 28 in the form of an internally reinforced rubber ring,the reinforcement being indicated by reference numeral 30, and therubber by reference numeral 3L Reference numeral 32 indicates a clampingring which is in threaded engagement with the threads 25 and is adaptedto clamp the rings 28 and 28' against the shoulder 21. The supportingring 28 is formed with a spider 33 which has a central portion 34 spacedinwardly from the inner surface of the ring 28, such central portionhaving a downwardly extending threaded projection 35 and being providedwith a central passage 36 carrying a packing gland 31 through which avalve stem 38 slidably extends. The upper end portion of the valve stem38 is provided with a valve 39 which is adapted to be moved downwardlyinto engagement with the valve seat 29 by the pressure of thecirculating fluid when the pump 20 is'operated. The lower end of thevalve stem is provided with a universal joint 40 whereby a pendulum 4|is suspended for universal movement.

In this form of our invention the downwardly extending projection 35 isin threaded engagement with a case 44, such case having a spider plugmountedin its lower end and having an inwardly extending'flange 46formed at an intermediate point thereon. The flange 46 carries a'yieldable member in the form of a coil spring 41,

the upper end of which engages a washer 48 which is fixed to the valvestem 38. f This washer is normally heldin spaced relation with thebottom of projection 35 by a plurality of downwardly extendingprojections or bosses 50. In this manner the washer is completelysurrounded by a fluid contained within the case 44 so that the valve andits associated parts are hydrostatically balanced when there is no flowof fluid through the pipe, as will be hereinafter more fully explained.The bottom plug 45 is provided with an internally threaded recess 52which is adapted to receive a pendulum rest 53. The case 44 serves toprotect the pendulum and its associated parts from the action of thedrilling fluid.

In the operation of the device, it will be understood that the drillpipe is filled with a fluid, such as the rotary mud, and it is importantthat the valve be hydrostatically balanced when there is no flow offluid through the pipe so that the spring 41 may be effective tomaintain the valve in a normal upward position regardless of the depthto which the instrument is lowered into the well. For accomplishingthis, we propose to fill the case 44 with a liquid such as oil, and toprovide a pair of oppositely operated check valves 55 and 56 in thelower end portion of the case. In this manner we balance the pressure onthe area of the valve stem at the top of the valve 39 with acorresponding pressure on a corresponding area on the pendulum.

It will be seen, therefore, from the construction so far described, thatwhen the pump is not operating, there being no flow of fluid through thepipe and the barrel and no differential pressure above the valve, thevalve 39 will be forced to the position shown in Fig.2 by the action ofthe coil spring 41. When the pump is started the differential pressurebetween the region above and below the valve will cause the valve tomove downwardly, and in the event the barrel is vertical such downwardmovement forces the tip 58 of the pendulum into the position A whereitengages the upper surface of the pendulum rest 53, the valve 38 beingmoved to the position A. In the event the pipe is tilted at an anglewith the vertical, the angle being such that the tip of the pendulumclears the pendulum rest, the pendulum is forced into position '3 ofFig. 2, and the valve 39 moves to the position B where it rests upon thevalve seat 29. When the valve is in the position A, it will be observedthat the area of the annular opening surrounding the valve has notchanged materially from the area of the annular opening which surroundsthe valve when it is in the full line or neutral position. There will,therefore, be no sensible indication of an increase in pressure at thesurface of the ground when the valve moves into this position. When thevalve is forced to the position B, however, the passage through thedrill pipe is completely restricted and there will be an immediateincrease in pressure observed on the gauge 2|, such increase in pressurebeing suflicient to stop or stall the pump 20 in the event the operatordoesv not stop the pump as as soon as the increase in pressure isobserved.

In order that there may be a direct axial thrust through the pendulumand the universal joint 40 when the tip of the pendulum engages thependulum rest, we provide the pendulum rest with an upper concavesurface, and point the tip of the pendulum 550 that the pendulum isalways 'centeredonthe' rest regardless of the point at which it makescontact.

It was pointed out as onejof the objects of this inventionto produce ade'vice of the" class described which can be adjusted so as to operatewhen the drill stem is inclined beyond various predetermined angles.This adjustment is accomplished by using pendulum rests of variousdiameters, since the inclination at which the valve is closed dependsentirely upon the extent to which the pendulum may swing before itclears the pendulum rest. Means are preferably provided whereby thependulum is definitely engaged by its rest as long as the inclination iswithin the predetermined limits at which the device is intended toremain inoperative, and just as definitely clears the rest to permitoperation of the device as soon as the inclination exceeds saidpredetermined limits. For this purpose the rest 53 is arranged so thatwhen the inclination is just at said predetermined limits, the pointedtip of the pendulum does not engage a flat abutment surface of the restsuch as might cause the pendulum to hang up, but engages a part of therest which provides merely a line contact whereby the pendulum isprevented from hanging up but must either swing outwardly beyond saidline for completely clearing the rest and permitting operation of thedevice, or is definitely confined within the predetermined limits so asto prevent operation of the device. As an instance of such line contactthe upper concave surface of the rest may be continued all the way tothe outer side surface ofthe rest so as to meet said side surface atless than a rightangle and so as to form an abutment edge I53 whichprovides merely a line contact and not a plane surface contact.Consequently if the inclination is such that the pointed tip of thependulum engages exactly on the edge I53 it must immediately slide offto one side or the other, depending upon whether the inclination is justwithin or just beyond the predetermined limits.

In using the device, a pendulum rest, which will be cleared by thependulum when the required permissible inclination in the bore hole isexceeded, is first mounted in the base plug 45, and the barrel with thedrill pipe and Kelly is mounted on the bit l3. The drilling operation isthen started in the usual manner and verticality indications may beobtained at any desired intervals of depth as the hole progresses.

The procedure of obtaining an inclination .or verticality indicationconsists in first stopping the operation of the pump, after which thevalve is automatically lifted to the full line position shown in Fig. 2.The operation of the pump is then started and if no appreciable increasein pressure is observed, the driller knows that the bore hole has notdeviated beyond the inclination permitted by the size of the pendulumrest. If, however, a marked increase in pressure is observed, thedriller knows thatthe bore hole has deviated to such an extent that thependulum has cleared the pendulum rest, which is greater than thepermissible inclination, and the drill pipe must be lifted to the pointat which the last reading was taken, when the necessary steps are takento straighten the course of the bore hole. It is advisable to stop therotation of the drill pipe during the brief interval necessary forstopping and starting thepump.

In order to avoid the possibility of rotary mud, sediment, and the like,accumulating about the extending end portion of the valve stem, we pro-.

vide a rubber sleeve 60 which extends from the upper portion of thepacking gland 38 to the upper end of the valve stem. Also, in order toavoid cutting action on the sleeve and its associated parts, we providethe valve with a downwardly extending skirt 6|.

The modified form of our invention shown in Fig. 4, is similar inconstruction and operation to the form shown in Fig. 2, and the variousparts thereof corresponding to the parts in Fig. 2, are indicated by thesame reference numerals distinguished by the prime mark.

The chief feature of this modified form of our invention resides in theprovision of a float valve 89 which is slidably mounted on the valvestem 38' and is adapted to engage a-seat 66 which is I formed on theunderside of the seat ring 61. The float valve 69 is normally forcedupwardly toward the seat 66 by a coil spring 68 and is adapted to bemoved downwardly from the seat by the action of pressure fluid passingthrough the drill pipe or conduit. The valve 69 is provided with a skirtwhich corresponds in function to the skirt 8| on the valve 38 in Fig. 2,and the valve stem 38' may be provided with a sleeve 60 which has thesame function as the sleeve 68 of Fig. 2. The upper end portion of thevalve stem 38' is provided with a valve 39', and in this form of ourinvention we provide the valve with notches 18 which prevent thecomplete restriction of the passage through the barrel when the valve isclosed. The notches, however, do not prevent suflicient restriction toobtain an appreciable increase in pressure in the pumping or pressurefluid which may be observed on the gauge 2|.

The float valve 89 is adapted for use in districts where the drill pipeis floated into the well, and also acts as a blowout preventer sincethis valve will be automatically closed in the event the pressure in thewell below the valve is greater than the pressure of the pumped fluidabove the valve. Such an increase in pressure frequently occurs when thedrill bit enters regions of high gas pressure.

The modified form of our invention, shown in Fig. 6, is similar inprinciple of operation to the form described in connection'with Figs. 2and 4. In this device, however, thevalve is normally maintained in aclosed position, and is held in a closed position by the pendulum in theevent the drill pipe is inclined beyond a predetermined angle with thevertical. vWhen the drill pipe is vertical the valve is adapted to beopened by the pressure fluid. The observed results are, however, thesame as the observed results in the other forms since there is noobserved increase in pres; sure when the drill pipe is vertical ascontrasted with a marked increase of pressure when the drill pipe isinclined from the vertical.

In this form of our invention, reference numeral 15 indicates a barrelwhich is provided with an inner shoulder 16 adapted to carry asupporting ring 11. The upper edge of the supporting ring 11 is engagedby a seat ring 18 which in turn is shown as being in threaded engagementwith the threads 19 in the upper end portion of the barrel.

Reference numeral indicates a valve adapted to seat against the lowerface of the valve seat 8', such valve being mounted on'the upper end ofa valve stem 82 which extends downwardly through a passage 83 in aspider member 84 formed or mounted in the supporting ring 11. The lowerend of the valve stem carries a universal joint 86 which in turnsupports a pendulum 81. The lower end of the pendulum terminates in atip member 88 which is positioned in close proximity to a concavependulum rest' 89.

i pendulum when the drill pipe is vertical or is upon the area of theopening.

When the drill pipe is vertical or is inclined, as pointed out above,the valve is moved downwardly against the action of the spring 41a bytheaction of the pressure fluid into the dot and dash line position C. Whenthe drill pipe is inclined beyond the predetermined limits mentionedabove, the tip of the pendulum engages the surface of the pendulum restand the valve is held closed, the resultant restriction in the passagethrough the drill pipe causing a sensible increase {in pressure at thesurface of the ground.

Reference numerals 98 and 99 indicate screens which are positioned onopposite sides of the operating mechanism in order to prevent theadmission of sand and other abrasive material into such mechanism.

It will be apparent from-the foregoing description that the devicecontemplated by this invention, is of simple form and construction, andthat it is automatically operable to give a sensible indication ofinclination at the surface of the ground without the drilling equipmentexcept to stop the rotation of the drill pipe and stop and start thepump.

It is to be understood that, while we have herein described andillustrated certain preferred forms of our invention, the invention isnot limited to the precise construction described above, but includeswithin its scope whatever changes fairly come within the spirit of theappended claims.

We claim as our invention:

1. In combination with a drill pipe and a fluid pressure system forforcing a fluid therethrough, means for indicating whether or not saidpipe is vertical by a pressure change in said fluid pressure embodying:a valve stem reciprocably mounted in said drill pipe; a valve on saidvalve stem adapted to be moved downwardly by the pressure of said fluid;a seat for said valve; a pendulum on the lower end of said valvestem;and a pendulum rest below said pendulum, said rest being formed so as tobe engaged by said pendulum when said pipe is inclined from the verticalbeyond a predetermined minimum and thereby hold said valve againstmovement relative to said seat.

2. In combination with a drill pipe and a fluid pressure system for,forcing a fluid therethrough, means for indicating whether or not saidpipe is vertical by a pressure change in said fluid embodying: a valveseat in said pipe; a valve associated with said seat for restricting theflow of fluid through said pipe; and gravity actuated means associatedwith said valve and adapted to hold said valve against movement relativeto said seat when said pipe is inclined from the vertical beyond apredetermined minimum.

3. In combination with a drill pipe and a fluid pressure system forforcing a fluid therethrough, means forindicating whether or not saidpipe is vertical by a change in said fluid pressure embodying: a valveseat in said pipe; a valve above inclined within predetermined limits,depending said seat adapted to be forced into engagement with said seatby said pressure fluid; a valve stem secured to said valve; means forslidably supporting said valve stem; yieldable means associated withsaid valve stem for normally forcing said valve away from said seat; apendulum on the lower end of said valve stem; a rest of predeterminedarea mounted in said pipe below said pendulum and adapted to be engagedby the lower end of said pendulum thereby holding said valve away fromsaid seat when said pipe is vertical, and a second valve slidablymounted on said valve stem below said seat and adapted for seatingengagement therewith for floating the pipe into a well.

4. In combination with a drill pipe and a fluid pressure system forforcing fluid therethrough, means for indicating whether or not saidpipe is vertical by a change in fluid pressure embodying: a valve seat;a valve below said seat; a stem secured to said valve and extendingdownwardly therefrom; yieldable means for normally forcing said valveinto engagement with said seat; a pendulum on the lower end of saidstem; and a pendulum rest mounted in said pipe below said pendulum andadapted to be engaged by said pendulum and thereby hold said valveagainst move- 5. In combination with a drill pipe and a fluid pressuresystem for forcing fluid therethrough, means for indicating whether ornot said pipe is vertical by a change in fluid pressure embodying: avalve seat; a valve below said seat; a stem secured to said valve andextending downwardly therefrom; yieldable means for normally forcingsaid valve into engagement with said seat; a pendulum on the lower endof said stem; and a pendulum rest mounted in said pipe below saidpendulum and adapted to be engaged by said pendulum and thereby holdsaid valve against movement away from said seat by the action of apressure fluid when said pipe is inclined from the vertical, said restbeing provided with an opening of predetermined area to receive thelower end of said pendulum when said drill pipe is vertical therebypermitting the movement of said valve away from said seat by thepressure of said fluid.

6. In combination with a drill pipe and a fluid pressure system forforcing a fluid therethrough, means for indicating whether or not saidpipe is vertical by a change in said fluid pressure embodying: a valveseat in said pipe; a valve above said seat adapted to be forced intoengagement with said seat by said pressure fluid; avalve stem secured tosaid valve and extending downwardly therefrom; means for slldablysupporting said valve stem; yieldable means associated with said valvefor normally forcing said valve away from said seat; a pendulum on thelower end of said valve stem; a rest of predetermined area mounted insaid pipe below said pendulum and adapted to be engaged by the lower endof said pendulum thereby holding said valve away from said seat whensaid pipe is vertical; 8. second valve slidably mounted on said valvestem below said seat; and yieldable means for forcing said second valvetoward said seat.

7. For use in combination with a pipe and a fluid pressure system forforcing fluid therethrough, means for indicating whether or not saidpipe is vertical by a change in fluid pressure embodying a barreladapted to be mounted in said pipe; a valve seat in said barrel; aspider in said barrel below said seat; a valve stem slidably mounted insaid spider; a valve on said stem adapted to be forced into engagementwith said seat for-restricting the flow of fluid from said pipe throughsaid barrel; a pendulum on the lower end of said stem; a pendulum restmounted in said barrel below the point of suspension of said pendulumand adapted to be engaged by the tip of said pendulum for holding saidvalve away from said seat against the action of a pressure fluid, and asecond valve slidably mounted on said valve stem below said seat andadapted for seating engagement therewith for floating the pipe into awell.

8. For use in combination with a pipe and a fluid pressure system forforcing fluid there'- through, means for indicating whether or not saidpipe is vertical by a-change in fluid pressure embodying: a barreladapted to be mounted in said pipe; a valve seat in said barrel; aspider in said barrel below said seat; a valve stem slidably mounted insaid spider; a valve on said stem adapted to be forced into engagementwith said seat for restricting the flow of fluid from said pipe throughsaid barrel; a pendulum on the lower end of said stem; a pendulum restmounted in said barrel below the point of suspension of said pendulumand adapted to be engaged by the tip of said pendulum for holding saidvalve away from said seat against the action of a pressure fluid, saidpendulum rest being of smaller diameter than the distance through whichthe tip of the pendulum may swing, and a second valve slidably mountedon said valve stem below said seat and adapted for seating engagementtherewith for floating the pipe into a well.

'9. For use in combination with a pipe and a fluid pressure system forforcing fluid therethrough, means for indicating whether or not saidpipe is vertical by a change in fluid pressure embodying: a barreladapted to be mounted in said pipe; a valve seat in said barrel; aspider in said barrel below said seat; a valve stem slidably mounted insaid spider; a valve on said stem adapted to be forced into engagementwith said seat for restricting the flow offluid from said pipe throughsaid barrel; yieldable means associated with said valve stem for forcingsaid valve away from said seat; a pendulum on the lower end of saidstem; a pendulum rest mounted in said barrelbelow the point ofsuspension of said pendulum and adapted to be-engaged by the tip of saidpendulum for holding said valve away from said seat against the actionof a pressure fluid, and a second valve slidably mounted on said valvestem below said seat and adapted for seating engagement therewith forfloating the pipe into a well.

10. A device of a barrel adapted to form a part of a pressure fluidconduit; a valve seat mounted in said barrel; a spider in said barrelbelow said seat; a case mounted on the under side of said spider; avalve stem slidably extending through the top of said case; a valvemounted on said valve stem above said-valve seat; yieldable means fornormally forcing said valve away from said seat; a pendulum mounted insaid case on the lower end of said valve stem; a pendulum rest mountedin the bottom of said case in coaxial relation with said valve stem,said pendulum rest being of less diameter than said case and of a heightsuch that said valve is held away from said seat when the tip of saidpendulum engages said pendulum rest, and a second valve slidably mountedon said the class described embodying:

and adapted for seatfor floating the barrel valve stem below said seating engagement therewith into a well.

11. A device of the class described embodying: a barrel adapted to forma part of a pressure fluid conduit; a valve seat mounted in said barrel;a spider in said barrel below said seat; a case mounted on the underside of said spider; oppositely operating check valves in the bottomportion of said case; a valve stem slidably extending through the top ofsaid case; mounted on said valve stem above said valve seat; .yieldablemeans for normally forcing said valve away from said seat; a pendulummounted in said case on the lower end of said valve stem; a pendulumrest mounted in the bottom of said case in coaxial relation with saidvalve stem, said pendulum rest being of less diameter than said case andof a height such that said valve is held away from said seat when thetip of said pendulum engages said pendulum rest, and a second valveslidably mounted on said valve stem below said seat and adapted forseating engagement therewith for floating the barrel into a well.

12. A device of the class described embodying: a barrel adapted to forma part of a pressure fluid conduit; a valve seat mounted in said barrel;a spider in said barrel below said seat; a case a valve mounted on theunder side of said spider; op-

positely operating check valves in the bottom poriicn of said case; avalve stem slidably extending through the top of said case; avalve'mounted on said valve stem above said valve seat; yield-able meansfor normally forcing said valve away from said seat; a pendulum mountedin said case on the lower end of said valve stem; a pendulum restmounted in the bottom of said case in coaxial relation with said valvestem, said pendulum rest having a concave top surface of smallerdiameter than said case adapted to be engaged by the tip of saidpendulum upon a, downward movement of said valve thereby holding saidvalve away from said seat, and a second valve slidably mounted on saidvalve stem below said seat and adapted for seating engagement therewithfor floating the barrel into a well.

13. In combination with a drill pipe and a fluid v pressure system forforcing drilling fluid therethrough, means for indicating whether or notsaid pipe is vertical by a pressure change in said fluid embodying: avalve seating annulus in the passage through said pipe; a reciprocablevalve structure in said drill pipe associated with said valve seatingannulus and adapted to receive a thrust force from said drilling fluid;gravity actuated means associated with said valve structure andcontrolled by the verticality of said pipe for governingthe movement ofsaid valve structure relative to said valve seating annulus by saiddrilling fluid, and means for moving the valve structure into seatingengagement with the valve seating annulus for floating the drill pipeinto a. well.

14. In combination, a valve structure adapted for mounting in a drillpipe, gravity actuated means governing operation of the valve structurewhereby the valve structure restricts flow of fluid through the drillpipe when the drill pipe is inclined from the vertical, and means foroperating the valve structure to restrict flow of fluid through thedrill pipe for floating the drill pipe into a well.

15. In combination, a valve structure adapted for mounting in a drillpipe, and gravity actuated means governing operation of the valvestructure whereby the valve structure restricts flow of fluid throughthe drill pipe when the drill pipe is inclined from the vertical, thevalve structure being also adapted for operation to restrict flow offluid through the drill pipe for floating the drill pipe into a well.

16. In combination, a valve structure adapted for mounting in a drillpipe, and gravity actuated means governing operation of the valvestructure whereby the valve structure restricts flow of fluid throughthe drill pipe when the drill pipe is inclined from the vertical, thevalve structure being also adapted for operation ungovemed by thegravity actuated means for floating the drill pipe into a well.

17. In combination, a valve seating annulus adapted for mounting in adrill pipe and having a valve seating surface at each of its upper andlower sides, a valve above and cooperating with the upper valve seatingsurface, gravity actuated means holding the valve away from said uppervalve seating surface when the drill pipe is vertical, and a. secondvalve below and cooperating with the lower valve seating surface forfloating the drill pipe into a well.

18. In combination, a valve seating annulus adapted for mounting in adrill pipe and having a valve seating surface at each of its upper andlower sides, a valve above and cooperating with the upper valve seatingsurface, gravity actuated means holding the valve away from said uppervalve seating surface when the drill pipe -is vertical but permittingmovement of the valve toward said upper valve seating surface forrestricting flow of fluid through the drill pipe when said pipe isinclined from the vertical, and a. second valve below and cooperatingwith the lower valve seating surface for floating the drill pipe into awell.

19. In combination, a restricted passageway in the bore of a drill pipe,a valve above and movable toward said restricted passageway, a stem forthe valve, gravity actuated means for holding the valve away from therestricted passageway when the drill pipe is vertical, and a secondvalve slidable on the stem below and movable toward the restrictedpassageway for floating the drill pipe into a well.

20. In combination, a restricted passageway in the bore of a drill pipe,a valve above and movable toward said restricted passageway. and meansfor holding the valve away from the restricted passageway when the drillpipe is vertical but permitting movement of the valve toward therestricted passageway when the drill pipe is inclined from the vertical,said means including v a rest and a gravity actuated device havingcooperating abutments adapted for contact within predetermined limits ofinclination of the drill pipe and adapted to clear one'another beyondsaid predetermined limits, said abutments presenting not more than aline of contact each to the other when the inclination of the pipe is atsaid predetermined limits.

21. In combination, a restricted passageway in the bore of a drill pipe,a valve above and movable toward said restricted passageway, and meansfor holding the valve away from the restricted passageway when the drillpipe is vertical but permitting movement of the valve toward therestricted passageway when the drill pipe is inclined from the vertical,said means including a rest and a gravity actuated device havingcooperating abutments adapted for contact within predetermined limits ofinclination of the drill pipe and adapted to clear one another beyondsaid predetermined limits, said abutments when contacting providing aninclined contact for centerlng the gravity actuated device relative tothe rest.

22. In combination, a restricted passageway in the bore of a drill pipe,a. valve above and movable toward said restricted passageway, and meansfor holding the valve away from the restricted passageway when the drillpipe is vertical but permitting movement of the valve toward therestricted passageway when the drill pipe is inclined from the vertical,said means including a pendulum having a pointed tip and a rest belowthe pendulum having an upper concave surface sloping downwardly to itscenter all the way from its outer periphery.

23. In combination, a valve adapted for mounting in a drill pipe, arest, and gravity actuated means adapted to engage said rest and holdthe valve in position restricting flow of fluid through the drill pipewithin predetermined limits in the inclination of the pipe.

24. In combination, a valve adapted for mounting in a drill pipe,a-rest, and gravity actuated means adapted to engage said rest and holdthe valve in position restricting flow of fluid through the drill pipewhen the pipe is inciined from the vertical.

25. In combination, a restricted passageway in the bore of a drill pipe,a valve reciprocable in the drill pipe relative to said passageway, astem for the valve, a guide for the stem,- and a protecting sleeve onthe stem adapted to yield to permit retraction of the stem relative totheguide.

THEODORE L. LYNCH. HARRY L. RILLING.

